This invention relates to the ceramic substrates for electronic circuitry, and, more particularly, substrates produced by firing at low temperatures.
High dielectric constant ceramic substrates are needed for the production of electronic circuitry. Economics of circuit manufacture dictate that the dielectric substrate and electrode metallization applied thereto be fired simulanteously. Since barium titanate-based materials (a commonly employed dielectric substrate) sinter into coherent dielectric bodies at temperatures in the range 1200-1400.degree. C., the electrode materials must have high melting points (to preserve pattern definition during firing), and likewise should not react with the substrate during firing. Therefore, expensive high-melting precious metals and alloys thereof have been used as electrodes. For example, U.S. Pat. No. 3,456,313 describes high dielectric constant capacitors using palladium or platinum electrodes. There is a need for dielectric substrates which may be fired at temperatures of 1200.degree. C., or below, and preferably below 1100.degree. C., and, hence, may be employed with lower cost noble metals, such as silver.